title: Differential IFN-γ production by adult and neonatal blood CD56+ natural killer (NK) and NK-like-T cells in response to Trypanosoma cruzi and IL-15.
abstract: Early interferon-gamma (IFN-γ) release by innate cells is critical to direct type 1 immune response able to control intracellular pathogens like Trypanosoma cruzi. Although CD56(bright) natural killer (NK) cells are reported to be potent early IFN-γ producers, other CD56(+) cells like CD56(dim) NK cells and NK-like T cells have recently been shown to also release IFN-γ. We have here studied the contribution of each CD56(+) lymphocyte populations in early IFN-γ production in both adults and neonates. On this purpose, we analysed the kinetics of IFN-γ production by RT-PCR, ELISA and flow cytometry from 2 h onwards after T. cruzi and IL-15 stimulation and sought for the responding CD56(+) cells. CD56(bright) and CD56(dim) CD16(-) NK cells were the more potent IFN-γ early producers in response to IL-15 and parasites in adults and neonates. In both age groups, the majority of IFN-γ producing cells were NK cells. However, on the contrary to neonates, CD3(+) CD56(+) NK-like T cells and CD3(+) CD56(-) 'classical' T cells also contributed to early IFN-γ production in adults. Altogether, our results support that whereas NK cells responded almost similarly in neonates and adults, cord blood innate CD56(+) and CD56(-) T cells displayed major quantitative and qualitative defects that could contribute to the well-known neonatal immune immaturity.
authors.affiliation: Laboratoire de Parasitologie, Faculté de Médecine, Université Libre de Bruxelles (U.L.B.), Brussels, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Guilmot
authors.forename: Y
authors.initials: Y
authors.lastname: Carlier
authors.forename: C
authors.initials: C
authors.lastname: Truyens
mesh_terms: D000328:Adult; D019002:CD56 Antigen / Q000032:analysis; D014355:Chagas Disease / Q000276:immunology / Q000469:parasitology; D005312:Fetal Blood / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D007231:Infant, Newborn; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000235:genetics; D019409:Interleukin-15 / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D007700:Kinetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000276:immunology*
chemical_list: D019002:CD56 Antigen; D019409:Interleukin-15; D012333:RNA, Messenger; D007371:Interferon-gamma
keywords: Interferon-gamma; T cell; Trypanosoma cruzi; human neonate and adult; innate immunity; natural killer cell